A contact wound favors suicide (37,49,55,63). Most multiple self-inflicted firearm wounds are contact (22,51,55,57,67,96,101,109,111,117,120,128,129). Other muzzle-to-
target distances are possible (16,128,130). In a Dallas, TX, study, all 199 suicides by a single gunshot wound to the head were contact, compared with 11 (9%) of 119 homicides (63). Only two noncontact wounds were seen in a database of 1200 firearm suicides. In a New Mexico-South Carolina study of 77 suicidal firearm wounds, 97% were contact and 3% were intermediate. Of the homicides, 10% were contact. In the same series, one of four accidents were contact, and the other three were intermediate range (Fig. 4; ref. 30). In a Texas study, 97% of wounds were contact, 2% intermediate, and 1% contact/intermediate (32).
Contact-range wounds are characterized by soot outside or inside the wound (16,73,92,93). The amount of soot can be considerable in certain situations: use of a
percussion handgun in which the combustion of propellant is incomplete; use of a bullet smaller in caliber relative to the weapon, which results in a large amount of unburned ammunition powder being deposited; discharge of weapon more than once through same entry (Fig. 13; refs. 69 and 131).
Soot is obscured by dried blood, drying of skin, decomposition, and charring (Fig. 14). Subcutaneous hemorrhage can also darken the wound edge. Soot can be absent in a contact wound if a long-barrel .22-caliber rifle is used, because the small powder load burns more completely in the barrel (see Heading 24.; Fig. 15; and refs. 16 and 132). In some instances, unusual material is present in the wound (e.g., blue Teflon plug material from a .38 special Glaser Safety slug ).
Angled contact and near-contact wounds result in eccentric deposition of soot (16). If the muzzle of the fired weapon is angled and in contact with the skin, then powder is deposited on the part of the entry away from the muzzle. This pattern will indicate the direction of projectile travel (Fig. 16). If the muzzle is angled and not touching the skin, then powder deposits only on the part of the entry close to the muzzle. The powder does not have sufficient density to reach the opposite surface of the entry. This pattern indicates direction from which the projectile originated (Fig. 17). Radiography and wound track documentation assist in differentiating between angled contact and angled near contact wounds (see Heading 16.).
In about 50% of contact wounds of the forehead, temple, and neck inflicted by a .22-caliber rimfire rifle, a pencil-like zone of blackened and seared skin extends
downward from the entry (Fig. 18). This is caused by a jet of hot gas and soot burning the skin, because either the lower margin of the barrel is not in contact with the skin ("incomplete" contact) or the muzzle slides down because of gravity (16,133,134).
Soot deposition and stippling (cylinder gap effects) can be seen on the skin near the entry (Fig. 19; refs. 16, 119, and 135). Unusual weapons (e.g., stud gun, nail gun) cause gas outlet burns (73). Symmetrical deposition of soot is seen if the pistol has a muzzle brake or vent (86).
Interposition of fabric can create stippling (see Heading 15.; Fig. 20; and refs. 16 and 59). "Pseudostippling" is characterized by separate abrasions caused by lead fragments sheared from a bullet as a result of misalignment of the cylinder and barrel of a handgun (16,58). A bullet can also fragment if objects are interposed between the muzzle and skin (136).
Distant self-inflicted wounds are rare (e.g., weapon held at arm's length, use of an assist device [16,37,49,124]).
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